masscan-to-subnets.py

#!/usr/bin/env python3
import sys
import ipaddress

if len(sys.argv) != 2:
    print("Usage: {} <file>".format(sys.argv[0]))
    sys.exit(-1)

with open(sys.argv[1]) as f:
    for line in f.readlines():
        line = line.strip()

        if not '-' in line:
            print(line)
        else:
            (ip1, ip2) = line.split('-')
            for net in list(
                    ipaddress.summarize_address_range(
                        ipaddress.IPv4Address(ip1),
                        ipaddress.IPv4Address(ip2))):
                print(net)